Nearly 90 miles of the historic Tigris River will soon be turned into a vast reservoir as Turkey completes the massive Ilisu Dam. While the government touts the project as a source of carbon-free electricity, it will displace 80,000 people and threaten a host of species.

Ken Sleight remembers the stunning beauty of Glen Canyon before it was flooded by a massive dam in the 1960s. Taylor Graham’s film “Seldom Seen Sleight” – winner of the Yale Environment 360 Video Contest – shows the magnificent landscape lost and offers hope it might someday be restored.

A popular surfing beach was closed Saturday after a cliff collapsed, sending tons of sandstone onto beachgoers and killing three people. A 30-foot-long slab of the cliff plunged onto the sand near Grandview Beach north of San Diego.

Many of the United States’ 91,000 dams are aging and sorely in need of repairs that could collectively cost tens of billions of dollars. Experts are increasingly worried that as extreme precipitation events increase, dams are at greater risk of failure, threatening lives and posing environmental risks.